👤 Sarah E Ferrara

Efficient, spatially selective delivery of adeno-associated virus (AAV) therapeutics to deep brain structures remains a major challenge to gene therapy for Alzheimer's disease (AD), owing to limited transport across the blood-brain barrier (BBB) and poor penetration to target neurons. Here, we establish an integrated, noninvasive imaging and therapy platform that combines microbubble-enhanced focused ultrasound (MB-FUS) with positron emission tomography/computed tomography (PET/CT) to transiently modulate the BBB, enhance region-specific AAV delivery following systemic dosing, and longitudinally track transduction in vivo. Optimized MB-FUS achieved targeted hippocampal delivery of systemically administered AAV9 in healthy mice, resulting in a 10-fold enhancement of neuronal transduction as compared to non-FUS controls. Importantly, longitudinal PET reporter gene imaging in the 5xFAD AD model demonstrated robust brain AAV transduction that remained stable for at least seven months. Finally, to assess therapeutic impact, we used brain-derived neurotrophic factor (BDNF) as a test cargo. MB-FUS-facilitated delivery elevated BDNF expression in targeted regions and produced short-term improvements in synaptic signaling in 5xFAD mice. Collectively, these results highlight MB-FUS as a next-generation delivery platform to overcome barriers to AAV therapeutic delivery in Alzheimer's disease and position longitudinal PET assessment as a critical, translatable tool for monitoring and optimizing gene therapy. Show less

Congenital hypogonadotropic hypogonadism (CHH) is a rare and genetically heterogeneous disorder characterized by absent or incomplete puberty due to impaired gonadotropin-releasing hormone (GnRH) function. A subset of individuals with CHH also present with developmental anomalies, including midline defects such as cleft lip and/or palate (CLP). This study investigates the genetic overlap between CHH and CLP. A total of 336 individuals diagnosed with CHH were clinically assessed for associated phenotypes, including CLP. High-throughput sequencing was performed using a targeted gene panel encompassing known CHH- and CLP-related genes. Variants were analyzed and classified according to the American College of Medical Genetics and Genomics (ACMG) criteria for pathogenicity. CLP was present in 21 patients with CHH (6%). Pathogenic or likely pathogenic variants in genes associated with both CHH and CLP-such as FGFR1 and CHD7-were identified in eight individuals. Furthermore, 17% of the patients with CHH without CLP harbored deleterious variants in genes implicated in clefting, including DVL3, PLCB4, NIPBL, and EDNRA. Evidence of digenic inheritance involving both CHH- and CLP-related genes was observed in multiple cases. FGFR1 variants were the most frequently detected and were commonly associated with anosmia and additional developmental anomalies. These findings highlight a genetic and phenotypic continuum between CHH and CLP, underscoring the involvement of shared developmental pathways. The high prevalence of FGFR1 variants in patients with CHH and CLP supports its role as a pleiotropic gene. Understanding the overlapping genetic mechanisms may enhance diagnostic precision and inform personalized management strategies for affected individuals. Show less

Familial hypercholesterolaemia (FH) is a hereditary disorder characterised by elevated low-density lipoprotein cholesterol (LDL-C) levels, substantially increasing the risk of atherosclerotic cardiovascular disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) targeting therapies, including monoclonal antibodies and small interfering RNA (siRNA) agents, have emerged as effective lipid lowering therapies. To assess the efficacy and safety of PCSK9-targeting therapy on lipid biomarkers and adverse events in patients with FH, compared with placebo on the background of standard lipid-lowering therapy. A systematic review and meta-analysis were conducted, incorporating data from 23 randomised controlled trials involving adult and paediatric FH patients treated with PCSK9 inhibitors (PCSK9i) or siRNA, including alirocumab, bococizumab, evolocumab, tafolecimab and inclisiran. Eligible studies reported changes in LDL-C, apolipoprotein B (ApoB), lipoprotein a (Lp(a)), triglycerides (TGL) and adverse effects. Pooled mean differences (MDs) and ORs with 95% CIs were calculated using random-effects models, and heterogeneity was assessed with I² statistic. This meta-analysis was registered on PROSPERO (CRD42025631510). A total of 4282 patients were included. PCSK9-targeting therapies significantly reduced LDL-C levels compared with control therapies (MD=-46.64%; 95% CI -50.77% to -42.52%; p<0.00001) and TGL (MD=-15.18%; 95% CI -19.34% to -11.03%; p<0.00001). Significant reductions were also observed for ApoB (MD=-34.94%; 95% CI -40.89% to -28.99%; p<0.00001) and Lp(a) (MD=-22.7%; 95% CI -25.95% to -19.44%; p<0.00001). LDL-C, TGL and ApoB reduction were more significant in heterozygous FH patients than in homozygous patients. The safety profile of these therapies was favourable, with adverse event rates comparable to those of the controls. PCSK9i and Inclisiran demonstrate significant and sustained reductions in LDL-C, ApoB, Lp(a) and TGL in FH patients, especially in heterozygous FH patients. These agents are generally well-tolerated and represent effective treatment options for FH patients inadequately controlled by standard lipid-lowering therapies. Show less

Statins are crucial for both the prevention and management of atherosclerotic cardiovascular disease (ASCVD). However, even with optimized statin therapy, a significant residual risk of ASCVD remains, highlighting the need for innovative approaches to lipid-lowering therapies (LLT) that more effectively target low-density lipoprotein cholesterol (LDL-C) and other atherogenic lipoproteins. Recently, novel pharmacologic agents have been introduced for the management of dyslipidemia. Bempedoic acid, an inhibitor of ATP citrate lyase, has emerged as a promising alternative for patients who exhibit statin intolerance. Moreover, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have transformed the management of hypercholesterolemia by reducing LDL-C levels. PCSK9 is a protein that mediates LDL receptor degradation; its inhibition enhances LDL receptor recycling, facilitating increased LDL-C uptake. New antisense oligonucleotides targeting apolipoprotein C3 (apoC3), ANGPTL3, and lipoprotein(a) have demonstrated significant reductions in these molecules, offering potential therapeutic advantages for certain dyslipidemias. Ongoing research is also evaluating apolipoprotein A1 (apoA1) to leverage the protective effects of high-density lipoprotein cholesterol (HDL-C), though conclusive clinical evidence is still required. This review examines the mechanisms and clinical efficacy of emerging LLT other than statins, focusing on bempedoic acid and PCSK9 inhibitors. Bempedoic acid acts upstream in the cholesterol biosynthesis pathway, offering a potentially safer option for patients intolerant to statins. PCSK9 inhibitors enhance LDL receptor recycling, significantly lowering LDL-C levels and reducing cardiovascular risk. A deeper understanding of these mechanisms is essential for the advancement of therapeutic strategies in dyslipidemia and cardiovascular disease management. Show less

Neurexins (NRXNs) are presynaptic terminal proteins and candidate neurodevelopmental disorder susceptibility genes; mutations presumably upset synaptic stabilization and function. However, analysis of human cortical tissue samples by RNAseq and quantitative real-time PCR at 8-12 postconceptional weeks, prior to extensive synapse formation, showed expression of all three NRXNs as well as several potential binding partners. However, the levels of expression were not identical; NRXN1 increased with age and NRXN2 levels were consistently higher than for NRXN3. Immunohistochemistry for each NRXN also revealed different expression patterns at this stage of development. NRXN1 and NRXN3 immunoreactivity was generally strongest in the cortical plate and increased in the ventricular zone with age, but was weak in the synaptogenic presubplate (pSP) and marginal zone. On the other hand, NRXN2 colocalized with synaptophysin in neurites of the pSP, but especially with GAP43 and CASK in growing axons of the intermediate zone. Alternative splicing modifies the role of NRXNs and we found evidence by RNAseq for exon skipping at splice site 4 and concomitant expression of KHDBRS proteins which control this splicing. NRXN2 may play a part in early cortical synaptogenesis, but NRXNs could have diverse roles in development including axon guidance, and intercellular communication between proliferating cells and/or migrating neurons. Show less

Familial hypertrophic cardiomyopathy (HCM), frequently caused by sarcomeric gene mutations, is characterized by cellular dysfunction and asymmetric left-ventricular (LV) hypertrophy. We studied whether cellular dysfunction is due to an intrinsic sarcomere defect or cardiomyocyte remodelling. Cardiac samples from 43 sarcomere mutation-positive patients (HCMmut: mutations in thick (MYBPC3, MYH7) and thin (TPM1, TNNI3, TNNT2) myofilament genes) were compared with 14 sarcomere mutation-negative patients (HCMsmn), eight patients with secondary LV hypertrophy due to aortic stenosis (LVHao) and 13 donors. Force measurements in single membrane-permeabilized cardiomyocytes revealed significantly lower maximal force generating capacity (Fmax) in HCMmut (21 ± 1 kN/m²) and HCMsmn (26 ± 3 kN/m²) compared with donor (36 ± 2 kN/m²). Cardiomyocyte remodelling was more severe in HCMmut compared with HCMsmn based on significantly lower myofibril density (49 ± 2 vs. 63 ± 5%) and significantly higher cardiomyocyte area (915 ± 15 vs. 612 ± 11 μm²). Low Fmax in MYBPC3mut, TNNI3mut, HCMsmn, and LVHao was normalized to donor values after correction for myofibril density. However, Fmax was significantly lower in MYH7mut, TPM1mut, and TNNT2mut even after correction for myofibril density. In accordance, measurements in single myofibrils showed very low Fmax in MYH7mut, TPM1mut, and TNNT2mut compared with donor (respectively, 73 ± 3, 70 ± 7, 83 ± 6, and 113 ± 5 kN/m²). In addition, force was lower in MYH7mut cardiomyocytes compared with MYBPC3mut, HCMsmn, and donor at submaximal [Ca²⁺]. Low cardiomyocyte Fmax in HCM patients is largely explained by hypertrophy and reduced myofibril density. MYH7 mutations reduce force generating capacity of sarcomeres at maximal and submaximal [Ca²⁺]. These hypocontractile sarcomeres may represent the primary abnormality in patients with MYH7 mutations. Show less